Vigilance urged to keep pests out of waterways

Southland water enthusiasts are urged to be vigilant about keeping their equipment clean, in an effort to prevent freshwater pests, like lake snow from entering the region’s waterways.

Lake snow is a slimy algae that has been discovered in Lakes Wanaka, Wakatipu and Hawea, causing costly problems for water users by clogging filters and accumulating on fishing lines and lures.

Environment Southland scientist James Dare said monitoring has been carried out on lakes in Te Anau and Manapouri, with no signs of lake snow spotted so far.

“It’s very difficult to monitor every inch of every lake in Southland, so we can’t be sure that it hasn’t made it into the region, but we have yet to see any evidence of it.”

Although it is not toxic and poses no known human health risk, the lake snow is unpleasant and sticks to wetsuits, skin and hair, as well as building up on equipment and causing blockages.

The origins of the lake snow in Otago and Queenstown are still unknown and the Otago Regional Council is working with researchers and the Ministry for Primary Industries to better understand lake snow and its impacts.

“At this stage there is no silver bullet for getting rid of lake snow, so like most pests, prevention is the best option,” Mr Dare said.

“It’s important that we protect our waterways from all freshwater pests by being very careful when transferring between lakes. People need to follow the Check, Clean, Dry messaging for all boats and equipment being transferred from one area to another, to ensure they are not carrying anything unwanted.

Anybody who thinks they have spotted Lake Snow should report it to Environment Southland on 0800 76 88 45.

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Additional information:

Lake snow is a sticky, biological material made up of diatoms – these are single cells of algae that form colonies. Lindavia intermedia are the algae species responsible for creating lake snow.

The lake snow algae secretes large amounts of polysaccharide, a glue-like substance, which cause the algae cells and other microscopic organisms to clump together on the water surface.